Illumination of Betrayal (裏切りの証明 Uragiri no Shōmei) is the nineteenth episode of Phi Brain: Kami no Puzzle Season One and the nineteenth episode of the anime series overall.
Kaito is visited by Gammon's little sister, Miharu, who is worried that she hasn't heard from Gammon. Meanwhile, Gammon arrives at the POG headquarters and is challenged by the Givers to earn the right to see Rook. He is eventually challenged by Rook's right hand man, Bishop, to face a puzzle in which he must manipulate lanes on a motorbike circuit to catch up to his opponent. Kaito and Nonoha are meanwhile approached by Elena, who tells them about Gammon joining the POG and gives Nonoha a puzzle which she solves herself. As Gammon clears the puzzle and earns the right to join Rook, Kaito experiences a strange reaction coming from the Orpheus bangle.